Sharp AQUOS LC-20D42U, Service Manual

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37
LC-20D42U
TROUBLESHOOTING TABLE
(Continued)
<Component video signal input> No video output (3)
No
Yes
Yes
Select INPUT-1 and the input signal on the input switching
menu screen.
When INPUT-1 cannot be selected since the characters
INPUT-1 on the menu screen are gray.
No video output from external input<<INPUT-1>>
Is INPUT-1 selected on the input switching menu screen?
Are component video signals fed to pins 21,23 and 25
(Y,Pb and Pr) of IC501 (AV SWITCH)?
Yes
Check between J507 and each input pin of IC501.
Check LCD_CONTROL PWB.
Is the component video signal detection function normal?
Check between 6 pin of J507 and pin 38 of IC501.
No
Yes
Are Y,Pb and Pr signals sent to pins 60,59 and 58 of
IC501 respectively?
Check IC501 and perpheral circuits.
No
Yes
Are component video signals sent to R574,R580,R586 Via
the Net of Q501-Q506?
Check between IC501 and SC501. (Q501-Q506,etc.)
No
Yes
Are Y,Pb and Pr signals fed to pins L26,J25 and J26 of
IC8101 (Broadcom) respectively? Via LPF composed of
Q2202,Q2203,Q2206,Q2210,Q2211 and Q2212.
Check IC8801.(Q2210,Q2211,Q2212,etc.)
No
Yes
Are digital video (LVDS) signals sent from pins 37-42 and
45-48 of IC2602?
Check IC2602 and peripheral circuits.
No
Are digital video (COMOS) signal sent from IC8101
(DVODATA 0-23,DVOCLKO,DVODE,DVOHSYHC,
DVOVSYNC)?
Check IC8101 and peripheral circuits.